1. Field of the Invention
The present invention relates to woven, endless tire reinforcement belts.
In recent years, endless woven tire reinforcement belts have been shown to provide a number of advantages over breaker belts of more conventional construction. According to the preferred method of production, these endless belts are woven from coated continuous reinforcement material by laying it in an ordered zig-zag pattern on the surface of a forming drum or other endless weaving surface.
It is an advantage of production that the woven belts are rapidly formed. Unfortunately, however, if it is desired to switch from production of reinforcement belts of one width to another, or one cord angle to another, or one thickness to another, it has been necessary in practice to make a number of adjustments to the weaving apparatus. These adjustments may be necessary, not just for a single production run, but also for each belt woven. Some of these adjustments may be mechanically complex and cumbersome, such that it is not economically feasible in a production setting to weave such belts. This problem is particularly acute if it is desired to weave a production series of single belts comprising multiple belt portions having different widths, thicknesses, or cord angles within each single belt.
It would be desirable to have a method and apparatus that would simplify the production of woven, endless tire reinforcement belts and provide flexibility in enabling rapid, economical changes in belt parameters such as width, thickness, and cord angle.
2. Discussion of the Prior Art
Tire reinforcement belt winding machines are known in the prior art. For example, U.S. Pat. No. 3,748,203 to Green shows in FIG. 1 thereof a schematic illustration of one form of apparatus for producing an endless reinforcement. In the '203 patent, the guides are interconnected by a cable and pulley arrangement. The drum and guides are driven by a motor. The guides are arranged through suitable mechanical linkage to reciprocate across drum surface transversely to the direction of rotation of the drum. A gear train includes a suitable arrangement of gears to control the movement of the guides with respect to the drum so that the strips are laid on the drum surface in a predetermined pattern.
The disadvantages of the '203 patent include the limitations imposed by the gear train. If it is desired to weave belts or belt portions having different predetermined patterns, such as differing cord angles, it is necessary to change the gearing ratios, such as for example by physically changing the gears. This is time consuming as well as cumbersome and can be prohibitively so where it is desirable to weave different patterns for each single tire reinforcement belt produced. Also, no provision is made in the '203 patent for producing belts where the two guides lay down strips having different cord angles that may differ from belt portion to belt portion within a single belt.
U.S. Pat. No. 4,600,456 to Oswald also shows a method and apparatus for forming woven endless tire reinforcing belts wherein the drive for the drum is a first electric motor and the drive for the weaving heads is a second electric motor. The relative speeds of the motors are synchronized by a phase lock loop controller and associated circuitry or other suitable servomotor control system. The phase lock loop controller will preferably be of the high gain, high accuracy type and can be set to a desired ratio of speeds for the two motors by suitable means such as a digital thumbwheel switch. In the preferred embodiment, the speed of the motor for the weaving heads will be monitored by an encoder which provides a reference signal to the phase lock loop controller. The speed of the drum drive motor will be monitored by an encoder, which also provides a feedback signal to the controller. The corrected drum drive speed is then provided to the motor by the controller. The guide means are arranged to function in mirrored relationship to one another.
The disadvantages of the '456 apparatus and method include the limitations that no provisions are made for producing belts wherein the cord angles may differ from belt portion to belt portion. For example, no provisions are made in the '456 patent for weaving the type of improved belts disclosed in copending application Ser. No. 929,602, filed Nov. 12, 1986, such as where a reinforcing belt is disclosed including a first belt portion having a first width W.sub.1 and cord angle A.sub.1 with a second belt portion having a second, narrower width W.sub.2 and a cord angle A.sub.2 woven onto the radially outward side of the first belt portion.
SUMMARY OF THE INVENTION
Apparatus is provided for weaving a woven endless tire reinforcing belt on an endless surface in a zig-zag pattern. The apparatus comprises input means for receiving information defining the zig-zag pattern, means for storing the information, central computer control means for reading the stored information and controlling the weaving of the belt as defined by the information, at least one endless weaving surface, means for continuously rotating the weaving surface under computer control, at least one reinforcement guide means for supplying cord reinforcement to the weaving surface, and at least one means for reciprocating the guide means under computer control. The computer controls the rotating means and the reciprocating means to reciprocate the guide means in timed relationship to the rotation of the weaving surface to effect the laying of said cord reinforcement on said surface in said zig-zag pattern in accordance with said information.
It is an object of the present invention to provide a programmable apparatus and method for forming endless tire reinforcing belts.
It is an object of the present invention to provide apparatus for forming endless tire reinforcing belts wherein the width of the belts woven can be readily changed from one belt portion to another.
It is a further object of the present invention to provide apparatus and a method for forming endless tire reinforcing belts wherein the cord angle of the belts woven can be readily changed from one belt portion to another.
It is a further object of the present invention to provide apparatus and a method for forming endless tire reinforcing belts wherein the thickness, or ply, of the belts woven can be readily changed from one belt portion to another.
Further attendant objects and advantages of the present invention shall become apparent from the following brief description of the drawings in light of the detailed description of the preferred embodiments.